1. Field of the Invention
The invention relates generally to the alteration of the ratio of the specific gravities of the oil and water phases resulting from the conversion of biomass to liquid products, which can further include the removal of metals and/or the modification of the conductivity, and more particularly to an effective means to reduce the level of solids contained in the oil phase. The invention also relates to using liquid-liquid extraction to partition desirable carbon containing compounds into the oil phase and undesirable carbon containing compounds into the water phase.
2. Description of the Related Art
In the conversion of biomass to liquid products, the product stream can contain both an oil phase and a water phase (containing both water present in the biomass prior to conversion, and water produced during the conversion process). Pyrolysis, in particular flash pyrolysis, has been proposed as one such process for converting solid biomass material to liquid products. Pyrolysis in general refers to a process in which a feedstock is heated in an oxygen-poor or oxygen-free atmosphere. If solid biomass is used as the feedstock of a pyrolysis process, the process produces gaseous, liquid, and solid products. It is often the case that the oil phase has a higher specific gravity than the water phase, resulting in the oil phase settling to the bottom of a settling vessel, and emulsions can also form between the oil and water phases. As a result, any solids present in the reaction products also settle into the oil phase, which can cause issues in downstream processing of the oil, and can be difficult and expensive to remove.
Thus, there is a need for an improved system whereby the solids content of biomass derived oil is reduced.
In addition, undesirable carbon containing compounds such as aldehydes and carboxylic acids can be present in the liquid product and such are not easily upgradable to transportation fuels. Such undesirable carbon containing compounds can be present in the oil phase while desirable carbon containing compounds can be present in the water phase, thus lowering the yield of high quality bio-oil for upgrading to fuels. Thus, there is also a need for an improved system whereby undesirable carbon containing compounds are transferred from the oil phase to the water phase and desirable carbon containing compounds are transferred from the water phase to the oil phase.